diff --git a/clients/js-legacy/package.json b/clients/js-legacy/package.json
index e45c157..45d474c 100644
--- a/clients/js-legacy/package.json
+++ b/clients/js-legacy/package.json
@@ -49,7 +49,7 @@
         "@solana/web3.js": "^1.95.5"
     },
     "dependencies": {
-        "@solana/codecs": "2.0.0"
+        "@solana/codecs": "6.9.0"
     },
     "devDependencies": {
         "@solana/prettier-config-solana": "0.0.6",
diff --git a/clients/js-legacy/src/instruction.ts b/clients/js-legacy/src/instruction.ts
index 44fc4a3..a4da08c 100644
--- a/clients/js-legacy/src/instruction.ts
+++ b/clients/js-legacy/src/instruction.ts
@@ -4,7 +4,7 @@ import {
     fixEncoderSize,
     getBooleanEncoder,
     getBytesEncoder,
-    getDataEnumCodec,
+    getDiscriminatedUnionCodec,
     getOptionEncoder,
     getUtf8Encoder,
     getStructEncoder,
@@ -106,7 +106,7 @@ export function createUpdateFieldInstruction(args: UpdateFieldInstruction): Tran
                     221, 233, 49, 45, 181, 202, 220, 200,
                 ]),
                 getStructEncoder([
-                    ['field', getDataEnumCodec(getFieldCodec())],
+                    ['field', getDiscriminatedUnionCodec(getFieldCodec())],
                     ['value', getStringEncoder()],
                 ]),
             ).encode({ field: getFieldConfig(field), value }),
diff --git a/clients/js-legacy/test/instruction.test.ts b/clients/js-legacy/test/instruction.test.ts
index 2641238..d6bd939 100644
--- a/clients/js-legacy/test/instruction.test.ts
+++ b/clients/js-legacy/test/instruction.test.ts
@@ -14,7 +14,7 @@ import {
     fixDecoderSize,
     getBooleanDecoder,
     getBytesDecoder,
-    getDataEnumCodec,
+    getDiscriminatedUnionCodec,
     getOptionDecoder,
     getUtf8Decoder,
     getU32Decoder,
@@ -86,7 +86,7 @@ describe('Token Metadata Instructions', () => {
             }),
             await splDiscriminate('spl_token_metadata_interface:updating_field'),
             getStructDecoder([
-                ['key', getDataEnumCodec(getFieldCodec())],
+                ['key', getDiscriminatedUnionCodec(getFieldCodec())],
                 ['value', getStringDecoder()],
             ]),
             { key: getFieldConfig(field), value },
@@ -106,7 +106,7 @@ describe('Token Metadata Instructions', () => {
             }),
             await splDiscriminate('spl_token_metadata_interface:updating_field'),
             getStructDecoder([
-                ['key', getDataEnumCodec(getFieldCodec())],
+                ['key', getDiscriminatedUnionCodec(getFieldCodec())],
                 ['value', getStringDecoder()],
             ]),
             { key: getFieldConfig(field), value },